In recent years, in the field of scanning probe microscopy, a probe is required to be sharpened from the viewpoint of the trend of a higher resolution. In response to the trend, Japanese Unexamined Patent Publication No. 276720/2005 proposes to form the tip of a probe with a single carbon nanotube or bundled plural carbon nanotubes (for example, about one to several tens nanometers in diameter).
When a conductive probe using carbon nanotubes (CNT) is used as the electron source of an electron microscope, some conductive probes have developed the problem in that the pattern of the electron beam is unstable and the emission current varies widely.